News & Events

Every War Must Aim for Peace

Image: Pawel Gaul; Getty Images

Marc Weller is Professor of International Law and International Constitutional Studies, University of Cambridge. Malik Dahlan is Emeritus Professor of International Law and Public Policy, Queen Mary University of London. This article first appeared in the New Law Journal.

War may well be another means of politics, as Carl von Clausewitz famously observed. But like Machiavelli, who had similar thoughts, Clausewitz is not an appealing character in the history of political philosophy. His views on the primacy of the national interest over ethics have remained as controversial now as they were when he first set pen to paper. Indeed, some may regard the firm denial of war as just another option of policy, a denial now enshrined in the Charter of the United Nations, as the principal achievement of civilisation since that time.

Self-defence applies

Of course, a defensive war remains legitimate, provided the strict conditions of self-defence enunciated in Art 51 of the UN Charter are met. Since 9/11, it is clear that self-defence can also be invoked against nonstate actors, in that case the al-Qaida terrorist movement. Clearly, the attack on Israeli civilians by Hamas is no less dramatic and severe for Israel than the attack on the twin towers was for the US. The taking of hostages has added to the entirely horrific nature of the situation, amounting to a further grave war crime.

In its Advisory Opinion of 2004 on the illegality of the wall constructed by Israel along the border with Palestinian territories the International Court of Justice at the Hague suggested that self-defence cannot be invoked in relation to threats or attacks emanating from the occupied territories. These were then still under the full military control of Israel. Last week a draft resolution on the situation in Gaza was vetoed by the US in the UN Security Council. This was in part because several states refused the US demand to include a reference to Israel’s right to self-defence in this instance.

Yet, since the at least partial Israeli withdrawal from Gaza in the wake of the Oslo Accords in 2005, few can seriously doubt that Israel is entitled to respond in self-defence to armed attacks mounted from those areas. However, Israel’s response must remain proportionate to the outrage that occasioned it. The trouble is, what seems proportionate to Israel, which sees its entire existence and identity under threat, may not seem so to others.

A National Liberation Movement?

On the other side of the equation, some have asserted that Hamas enjoys a positive right to wage war. International law has to some extent accepted the right of National Liberation Movements to engage in an armed struggle, although some Western states have resisted. But the doctrine of National Liberation only applies to groups struggling against classical colonial oppression. The Palestine Liberation Organization (PLO) was broadly taken to qualify. However, with the Oslo Accords, the PLO gave up any claim to an armed struggle in favour of self-determination. Instead, the people of Palestine are meant to advance their interests through the means of the Palestinian authority by peaceful means only.

Hamas, on the other hand, never qualified for that status. Many Western states have instead designated the organisation as a terrorist movement. Moreover, recognition of a right to struggle against foreign oppression was constructed in a way to enhance humanity also in the ‘new just wars’ against classical colonialism, rather than as a carte blanche for terrorism. Accordingly, the status of a national liberation movement implies the right to be treated as an international combatant in the confrontation with a colonial power. Thus, whatever the protestations of the colonial state that the conflict is entirely internal, the National Liberation movement can insist that the law of international armed conflict applies.

This branch of humanitarian law ordinarily only covers relations between states. It contains far more detailed limitations on the conduct of those fighting in the conflict than the more modestly established law on internal armed conflicts that would otherwise apply. Hence, even if Hamas could claim to be a National Liberation Movement, which it is not, it would still be required to respect the laws of armed conflict. The horrific slaughter of 1,400 men, women and children, mainly civilians, is the antithesis of such compliance.

Hamas might still argue that the case of Palestine has remained unaddressed for three quarters of a century, or at least since the 1967 war. If the international system does not offer a solution for the Palestinians, Hamas might calculate, then action outside of the system and its rules remains the only option.

Humanitarian law

At the same time, the West is emphasising that democracies must live by a higher standard of conduct than others. Hence, Western leaders counsel, Israel should choose to respect humanitarian law, even if Hamas manifestly does not.

This argument is dangerous. It seems to imply that, in the face of the atrocity committed by Hamas, Israel has the option to comply or not to comply with humanitarian law. However, the application of humanitarian law by one side is not dependent on compliance by the other. If the enemy executes prisoners of war, it is not lawful for the opposing side to execute captured combatants in response.

But if humanitarian law applies, which branch of it is it? Is it law of armed occupation, seeking to bestow maximum benefits on a population that has fallen under enemy control, or the rules of warfare, seeking to balance the necessities of military operations with the need to protect civilians?

No legal vaccum

Most argue that the law of armed occupation still applies. Israel formally withdrew its armed forces at least from Gaza in August 2005, while maintaining some aspects of direct occupation in certain areas of the West Bank. Even in Gaza, it is asserted, Israel has remained in ‘remote control’ of the territory ever since.

Israel continues to reach into Gaza and the West Bank at will, snatching or killing alleged militants or destroying homes and infrastructure in what commentators see as disproportionate retaliation for suspected acts of violence perpetrated by some Palestinians. It retains certain powers in relation to parts of the West Bank, including security-related. Both territories remain economically isolated and dependent on Israel in terms of food, energy and even water. Israel’s ability simply to switch off most of the life-sustaining services in Gaza has now demonstrated this once more. Access and freedom of movement by individuals is strictly regulated by Israel, with the exception of the one exit towards Egypt.

Others assert that Palestine has been recognised by some 138 states. Hence, the law of international armed conflict between states applies. Yet, the statehood of Palestine has not been fully actualised and remains contested, and Hamas, or Gaza, are in any event not coextensive with Palestine, the potential state.

In the end, though, the essential principles of humanitarian law are present in all these competing branches of humanitarian law. Whichever option one chooses, Gaza and the West Bank do not exist in a legal vacuum. The first principle is that of protection and distinction. A civilian population must not be made the object of a military campaign and must be isolated from the consequences of warfare.

Principle of distinction & protection of civilians

Israel appears to argue that civilian objects that contribute to the military effort of the other side may be attacked. ‘Since Hamas places its military infrastructure in the heart of the civilian population in the Gaza strip, including in residential houses, schools, mosques, and businesses, it is permissible to direct attacks towards these sites, as they have lost their civilian nature and become legitimate military targets due to this use,’ Colonel Sharvit Baruch, former head of the international law department within the Israel Defense Force, asserts.

This view would expose all in Gaza, and the entire civilian infrastructure, to military attack, as it is not likely known precisely which civilian objects are being used as cover by Hamas. If schools, mosques and allegedly even hospitals are fair game under this view, the protection afforded by humanitarian law would be undermined or effectively suspended.

Instead, the correct view is that Israel needs to identify and be able to justify which targets have a specific military purpose. Even then, the balance between the military advantage gained by attacking the site, and the risk to civilian lives would need to be clearly drawn. Wholesale attacks against civilian targets cannot be justified in this way.

Israel claims to evaluate each individual target slated for attack from the air in terms of likely civilian casualties. However, the present bombing campaign suggests that the toll imposed on civilians is already unacceptably high, presumably with far more to come.

Colonel Baruch answers that the enormous threat emanating from Hamas justifies even the loss of ‘many civilians in Gaza’, as such losses would not be disproportionate to the benefit Israel seeks to achieve in terms of its national security.

This argument must be rejected, as it mixes two concepts, strategic and tactical proportionality. As the strategic aims of Israel are supposedly overwhelmingly just and necessary, it is asserted, the tactical balance between military gain and civilian suffering can be re-adjusted in favour of the military dimension, at the expense of civilian protection.

At a strategic level, the doctrine of proportionality means that a state must not use force in excess of what is strictly necessary to exercise the right of self-defence. That is to say, proportionality determines to what extent force may be used—an aspect of the jus ad bellum. Yet, even if a significant amount of force can be used in self-defence, this does not remove the legal requirements governing how, or in what way, such force can be used. Essential principles of humanitarian law, of the jus in bello, must still be complied with.

At an operational or tactical level, proportionality requires that military gain in any specific armed action must not be out of proportion to the injury caused to civilians. Civilian casualties must remain incidental. Where civilian casualties cannot be avoided beyond a certain scale, the operation must not take place. Moreover, it is impermissible simply to rule in a blanket way that certain types of civilian installations, like schools or hospitals, or other places where terrified civilians have congregated, are tainted by virtue of possible military use by Hamas, and attack them at the cost of hundreds of civilian lives.

There is no right for a state to balance the question of compliance with core rules of humanitarian law against its national security interests and to essentially suspend the former in deference to the latter. This would render humanitarian law entirely without effect. All states would be tempted to rank their national security interests, or the operational safety of their soldiers, higher than the need to preserve civilian lives.

This means that Israel’s campaign needs to engage Hamas specifically and directly, rather than indirectly by addressing any civilian installation that may potentially be used or abused by it. This is admittedly more dangerous for the soldiers involved than a broad campaign of aerial bombardment. However, Israel cannot simply transfer the risks and dangers of the present operation on the civilian population, already corralled into a small space without any protection and in a situation of immense vulnerability. These very circumstances increase the requirements of protection and correspondingly limit the use of potentially indiscriminate tools of warfare.


The demand that the entire civilian population of Northern Gaza must leave if it does not wish to be destroyed is no answer to this problem. Some argue that this is a policy of giving due warning to populations at risk, in pursuit of compliance with the need to preserve civilian lives. Others argue that this is a deliberate policy of forced displacement which is evidently unlawful.

At a tactical level, it is appropriate to give warning to civilians if they are at risk of injury due to their proximity to a lawful military target. However, to remove an entire population of a large civilian area of over a million individuals, mostly women, children and the elderly, cannot ever fit under this justification. Again, such a policy transfers the risks and costs of a military campaign to those very individuals who are meant to be isolated from those risks and costs by virtue of humanitarian law. Israel cannot shift the responsibility for compliance with the principle of distinction between military and civilian objects on the civilians by simply demanding that all civilians must disappear. This finding is reinforced by the fact that the area of displacement, Southern Gaza, is also subject to significant air attacks and a policy of siege.

If the plan provides for the wholesale destruction of the entire civilian infrastructure in Northern Gaza, to ‘flush out the terrorists’ by leaving them isolated in a wasteland of rubble, this would simply be an inadmissible form of warfare. Moreover, even if the North of Gaza could be declared free of Hamas in this way, how would Israel address the South? Presumably Hamas would retreat there. Would over two million civilians then be carefully filtered and screened for terrorists and be herded into the destroyed North, while what remains of Gaza is subjected to similar treatment?

The policy of siege

In somewhat antiquated practice, it may have been lawful to besiege a heavily entrenched military position, that is, force it into surrender by depriving its garrison of munitions and essentials of life. Some argue that this doctrine now covers Israel’s policy of depriving Gaza of basic supplies.

In truth, of course, it would never be permissible to besiege an entire civilian population of millions by depriving it of drinking water, food and medicine, and the supply of energy to keep hospitals operating. Such action would not much affect the Hamas militants in the area, making it difficult to assert some sort of military necessity in support of it, even if such an argument could be admitted. Again, the actual victims would be the civilian population.

Such a policy, should it be maintained, would amount to a crime against humanity, as would any military strategy that simply shifts the burden of an armed confrontation from the military to the civilian population, concentrated in a small space and highly vulnerable to any form of attack. The International Committee of the Red Cross, which rarely takes positions on on-going conflicts in the interest of continued access to the sides, declared last week: ‘The instructions issued by the Israeli authorities for the population of Gaza City to immediately leave their homes, coupled with the complete siege explicitly denying them food, water, and electricity, are not compatible with international humanitarian law.’

Permission to bring in a small number of trucks carrying humanitarian supplies from Egypt does not change this picture. There is no alternative to the creation of humanitarian safe areas along with humanitarian corridors and humanitarian pauses in the fighting in order to guarantee the survival of 2.3m people. Indeed, as Israel spreads its control over Gaza in the course of the military campaign, the duty to ensure the supply of everything necessary for the survival of the population would increasingly fall on Israel itself, in addition to humanitarian organisations.

There is also no room for a policy of collective punishment, asserting that a population shares responsibility for horrific attacks mounted by Hamas, along with the taking of hostages and their presumed captivity in the territory concerned. Groups of this kind do of course not seek the permission of the affected populations when they implant themselves in civilian areas. Germany’s policy of collective punishment of places of resistance to occupation during World War II was rightly pursued in the reckoning administered by the criminal tribunals that followed.

Re-making the Middle East

Prime Minister Benjamin Netanyahu has announced that Israel is now at war with Hamas. There will be no more tit-for-tat responses to violence from Hamas, such as the endless series of rocket attacks mounted from Gaza and elsewhere. This war will, Netanyahu asserts, fundamentally change the face of the Middle East.

There is the fear that such a permanent reordering of the Middle East means that Palestinians will be permanently moved out of Gaza, or parts of it. The pressure on Egypt to open its borders and accommodate them in tents in the naked desert of the Sinai might point in that direction.

Of course, such an outcome would be unlawful and it would not be a solution to Israel’s security issues. As the past 70 plus years have shown, pushing Palestinians out into desolate refugee camps in neighbouring states does not extinguish their zeal for achieving their own state. It is precisely this life without any future perspective that furnishes the breeding ground for terrorism and another ‘Flood of Al-Aqsa.’

The problem is that it will not be possible to re-make the Middle East through unrestrained violence in Gaza. Rather, this is the most dangerous time for the region since the founding of Israel. Military escalation is possible or even likely. US Secretary of State Antony Blinken, backed by the British Prime Minister Rishi Sunak, has been travelling the region to try and persuade Arab states to help prevent a spreading of the conflict to the West Bank, Lebanon and potentially Iran, possibly in vain. Russia may use this present episode as cover for further damaging action in Syria. The presence of two US aircraft carrier task groups in the Mediterranean is a reminder of the serious nature of this threat and of the prospect of great power involvement in further escalation.

At present, Israel is in a position of significant strength, on the verge of, or by now in the process of, fully unleashing its vast military potential. However, the principal victim of such a massive use of military power will be a defenceless civilian population in danger of destruction or displacement. The sympathy for Israel as the victim of the dreadful outrage committed by Hamas will dissipate rapidly and turn into opposition and international opprobrium.

Administering yet another humiliating defeat over the people of Palestine and with them the Arab world just incubates the next round of even greater violence. Moreover, a further humanitarian catastrophe in Gaza would force all Arab states, under the principles of Siyassa Shariyya, to declare invalid their existing treaties and engagements vis-à-vis Israel.

Indeed, for Arab states, and many others, this likely development will further undermine the credibility of the rule of law and the Western liberal order altogether. When compared to Western criticism of Russian attacks on civilian targets in Ukraine, it advances the sense of Western double standards.

It is sadly unlikely that Israel can muster the grand and incredible courage to use this moment of great moral and military strength in order to achieve a real reordering of the Middle East. Instead of answering violence with yet more violence, one may ask whether great statesmanship could have turned this sad moment into an opportunity for a fundamental restructuring of the Middle East through maximum diplomacy, not maximum force.

In contrast to previous instances, the chance to address the issue of Palestine was quite unique. None of the regional states, other than perhaps Iran, are keen on a collapse of whatever regional stability there has been. With the assistance of China, even Iran seemed ready to reconsider its role in the region.

Moreover, finally, much of the Arab world had accepted without condition that Israel is a legitimate state in the region and merits diplomatic recognition. Part of this recognition would have been the understanding by all that no new economic and security order can emerge in the region if the Palestinian issue remains unaddressed.

Clausewitz’s dictum that war is the continuation of politics by another means has not remained unopposed, or at least unqualified. Since the dawn of time, all political philosophers and wise men and women since Aristotle have argued that war, if sometimes necessary, can only be legitimate if it is waged in order to achieve just and lasting peace at the end of it.

The government of Israel cannot evade its responsibility in this respect. It needs to be able to explain how its actions will contribute to lasting peace, rather than destroying any prospect for it. Any policy of force, even if triggered by the most profound provocation, that is not embedded in a clear and realistic avenue towards peace must ultimately fail. And any war that is conducted in violation of the most fundamental dictates of humanity cannot but be the breeding ground for yet more inhumanity and violence.